NAME

SYNOPSIS

DESCRIPTION

[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the
requirements described here and the ISO C standard is unintentional. This volume of IEEE Std 1003.1-2001 defers to
the ISO C standard.

The iswupper() function shall test whether wc is a wide-character code representing a character of class
upper in the program's current locale; see the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 7, Locale.

The wc argument is a wint_t, the value of which the application shall ensure is a wide-character code
corresponding to a valid character in the current locale, or equal to the value of the macro WEOF. If the argument has any other
value, the behavior is undefined.